This paper studies the effect of ground stress, pore gas pressure and adsorbed methane on methane transport in coal seam. and researches into the applleability of Darey’s inw to methane transport. The additional expa...This paper studies the effect of ground stress, pore gas pressure and adsorbed methane on methane transport in coal seam. and researches into the applleability of Darey’s inw to methane transport. The additional expansion stress of coal induced by adsorbed methane is measured. The paper establishes the constitutive equation of methane transport, taking ground stress, pore gas pressure and Klinkenburg’s effects into consideration. The features of methane transport under the condition of given stress or strain have been analyzed.展开更多
The existing bypotheses of coal and gas outburst mechanism are all based on the elasticity mechanies. Since they have not taken time factor into eonsideration, these hypotheses can not give a satisfactory explanation ...The existing bypotheses of coal and gas outburst mechanism are all based on the elasticity mechanies. Since they have not taken time factor into eonsideration, these hypotheses can not give a satisfactory explanation of the oceurrence and development of the outburst. A creep mathematital model of gas-contaming coal,which can better expdri the phenomenon of coal and methane outbursts,has been set up through creep tests and analyses under the condition of triaxiai compression.The tests have proved that there isn’ t essential difference between the rheological properties of outburst prone coal and non-outburst prone coal. Outburst can happen in any kind of coal if the rheologicai conditions exist. The creep mathematital model provides a soild foundation for establlshing a comprebcnsive criterion of coal and gas outburst.展开更多
Based on the statistical data of 26 outburst prone coal seams in China, this paper presents the relationship among the threshold gas pressure in coal and gas outburst and the volatile content and hardness of coal by m...Based on the statistical data of 26 outburst prone coal seams in China, this paper presents the relationship among the threshold gas pressure in coal and gas outburst and the volatile content and hardness of coal by mathematical statistics. The threshold value of gas pressure for outburst pmin in MPa may be calculated by formula Pmin =5(0. 1+0. 07Kf), where / is the hardness and V the volatile content (%) of a soft bed. In China, the value of Pmin of some outburst prone coal seams ranges from 0. 57 to 0. 1 MPa.展开更多
文摘This paper studies the effect of ground stress, pore gas pressure and adsorbed methane on methane transport in coal seam. and researches into the applleability of Darey’s inw to methane transport. The additional expansion stress of coal induced by adsorbed methane is measured. The paper establishes the constitutive equation of methane transport, taking ground stress, pore gas pressure and Klinkenburg’s effects into consideration. The features of methane transport under the condition of given stress or strain have been analyzed.
文摘The existing bypotheses of coal and gas outburst mechanism are all based on the elasticity mechanies. Since they have not taken time factor into eonsideration, these hypotheses can not give a satisfactory explanation of the oceurrence and development of the outburst. A creep mathematital model of gas-contaming coal,which can better expdri the phenomenon of coal and methane outbursts,has been set up through creep tests and analyses under the condition of triaxiai compression.The tests have proved that there isn’ t essential difference between the rheological properties of outburst prone coal and non-outburst prone coal. Outburst can happen in any kind of coal if the rheologicai conditions exist. The creep mathematital model provides a soild foundation for establlshing a comprebcnsive criterion of coal and gas outburst.
文摘Based on the statistical data of 26 outburst prone coal seams in China, this paper presents the relationship among the threshold gas pressure in coal and gas outburst and the volatile content and hardness of coal by mathematical statistics. The threshold value of gas pressure for outburst pmin in MPa may be calculated by formula Pmin =5(0. 1+0. 07Kf), where / is the hardness and V the volatile content (%) of a soft bed. In China, the value of Pmin of some outburst prone coal seams ranges from 0. 57 to 0. 1 MPa.
